unshadow

Combine system passwd and shadow

$ sudo unshadow /etc/passwd /etc/shadow

$ sudo unshadow [path/to/passwd] [path/to/shadow]

unshadow PASSWDFILE SHADOWFILE

unshadow combines /etc/passwd and /etc/shadow files to create a traditional Unix password file format. This unified format is required by password cracking tools like John the Ripper.
The utility is part of the John the Ripper project and is used in authorized password security auditing to prepare password hashes for analysis.

Requires root privileges to read shadow file. Should only be used for authorized security testing. Output contains sensitive password hashes.

unshadow was developed as part of the John the Ripper password cracker project to handle modern Unix systems that separate password hashes into the shadow file.

john(8), passwd(5), shadow(5)